CTEPH.com is designed to increase CTEPH disease awareness among HCPs, Bayer said, and to educate them on diagnosis and surgical treatment.

The site's debut follows the March EU approval of the drug Adempas (riociguat) for CTEPH and pulmonary arterial hypertension (PAH). The FDA sanctioned it for those indications in October. Bayer forecasts peak sales of 500 million euros ($694 million) in those two areas.

In CTEPH, blood clots and thromboembolic occlusion of pulmonary vessels lead to increased pressure in the pulmonary arteries. Symptoms can be nonspecific and indistinguishable from symptoms of other forms of PH, but, when properly diagnosed, it's potentially curable with pulmonary endarterectomy (PEA), a surgery in which the blood vessels of the lungs are cleared of clot and scar material.

Adempas is indicated for adults with inoperable CTEPH, or persistent or recurrent CTEPH after surgery. The oral therapy is the first of a class of medicines, sGC-stimulators. Studies have shown Adempas was associated with improved ability to walk farther, helping the heart and lungs work better and making breathing easier.

Each year, in the US, about 600,000 people have an acute pulmonary embolism (PE), with an estimated 500 to 2,500 new cases of CTEPH diagnosed annually. A diagnosis of CTEPH is often not correctly made in PH patients, because they have no overt history of PE.